JP3658359B2 - Sheet width control method in steel strip production line - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plate width control method in a steel strip production line having a tension leveler type scale breaker and a scale scraping brush device.
[0002]
[Prior art]
In order to remove the scale adhering to the surface of the hot-rolled steel strip, a tension leveler type scale breaker and a scale scraping brush device are installed in front of the pickling line.
This tension leveler type scale breaker makes it easy to crack and remove the scale by bending and stretching the steel strip by passing it between multiple rolls arranged in steps while applying tension to the steel strip. Device.
[0003]
Further, the scale scraping brush device is a device that scrapes off the scale, which is easily removed by the tension leveler type scale breaker, with a brush.
This scale scraping brush device is equipped with a backup roll paired with a brush roll to prevent unevenness of scale scraping due to warpage of the steel strip and uneven wear of the brush and to improve the scale scraping effect. Intermesh (step) is attached.
[0004]
Before and after the tension leveler-type scale breaker and scale scraping brush device, a bridle roll is installed to apply tension to the steel strip. This tension causes the steel strip to stretch several percent in the longitudinal direction. A phenomenon occurs in which the width of the steel strip shrinks by several mm.
In order to control the shrinkage allowance of this plate width, a plate width meter is provided before and after the tension leveler type scale breaker, but conventionally, the detection value of the plate width on the exit side of this tension leveler type scale breaker and preset Compared with the specified value, feedback control of the plate width was performed so that the plate width on the exit side of the tension leveler type scale breaker was within this specified range.
[0005]
However, in this method, since the reduction width of the plate width in the scale scraping brush device cannot be taken into account, the plate width on the exit side of the scale scraping brush device may be narrower than the specified range. .
As a method to consider the shrinkage margin of the plate width in the scale scraping brush device, it is conceivable to install a plate width meter in the subsequent stage of the scale scraping brush device, but in this case, the plate on the entrance side of the tension leveler type scale breaker The distance from the width meter to the plate width meter at the subsequent stage of the scale scraping brush device is 10 m or more, and there is a problem that feedback control of the plate width becomes impossible.
The equipment configuration of the tension leveler type scale breaker and the scale scraping brush device is disclosed in Japanese Patent Publication No. 2-47282, but the problem of plate width control which is the subject of the present invention is completely disclosed. Not.
[0006]
[Problems to be solved by the invention]
The present invention solves the problems of the prior art as described above, and in a steel strip production line having a tension leveler type scale breaker and a scale scraping brush device, a plate installed on the exit side of the tension leveler type scale breaker It is an object of the present invention to provide a method for performing high-precision sheet width control of a steel strip using a width gauge.
[0007]
[Means for Solving the Problems]
The present invention provides an output side of a tension leveler type scale breaker so that the plate width on the exit side of the scale scraping brush device is within a specified range from the detected value of the plate width meter installed on the exit side of the tension leveler type scale breaker. By determining the target value of the plate width in the case, a method for performing high-precision plate width control considering the plate width variation in both the tension leveler type scale breaker and the scale scraping brush device is provided. The following contents are as described in the claims.
[0008]
(1) In a steel strip production line having a tension leveler set scale breaker between a pair of bridle rolls that apply tension to the steel strip and a scale scraping brush device that scrapes off the scale that is easily removed by the breaker. A plate width control method for determining a target value of the plate width on the exit side of the tension leveler type scale breaker so that the plate width on the exit side of the scale scraping brush device falls within a preset specified range. A sheet width control method in a steel strip production line, characterized in that the sheet width is controlled so that the actual value of the sheet width on the exit side of the tension leveler type scale breaker approaches the target value.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a diagram for explaining a plate width control model in the present invention.
The hot-rolled steel strip enters from the right side of FIG. 1, and after the scale is removed by the tension leveler type scale breaker 2 (T / L) and the scale scraping brush device 3 (brush), FIG. It is transported to a pickling facility not shown on the left side.
A bridle roll 1 is installed on the entrance side of the tension leveler type scale breaker 2 and on the exit side of the scale scraping brush device 3 to apply tension to the steel strip.
[0010]
Plate width gauges 4 and 5 are installed in front of the entrance side bridle roll 1 of the tension leveler type scale breaker 2 and on the exit side of the tension leveler type scale breaker 2, respectively, and the exit side of the scale scraping brush device 3 is provided. The target value of the plate width at the exit side of the tension leveler type scale breaker 2 is determined so that the plate width at the preset level is within a predetermined range, and the actual value of the plate width at the exit side of the tension leveler type scale breaker 2 is determined. The plate width is controlled so that the value approaches the target value.
The reason why the entrance side plate width meter 4 of the tension leveler type scale breaker 2 is installed not in front of the tension leveler type scale breaker 2 but in front of the entry side bridle roll 1 is that T / This is because it is not necessary to install it immediately before L, and rather it is easier to control the plate width if the value of the inlet plate width is known earlier.
[0011]
A specific specific control flow is as follows.
First, a process computer (procone) 8 that controls the steel strip production line sends a target width value of the plate width to the controller 9. The controller 9 receives the detected values of the T / L inlet side plate width meter 4 and the T / L outlet side plate width meter 5 and the plate width on the outlet side of the scale scraping brush device 3 falls within a predetermined range. Thus, the target value of the plate width on the exit side of the tension leveler type scale breaker 2 is determined.
Further, the controller 9 sends a control signal to the elongation motor 7 of the bridle roll 1 so that the actual value of the plate width on the exit side of the tension leveler type scale breaker 2 approaches the target value, and the tension applied to the steel strip. To control the width of the plate.
[0012]
FIG. 2 is a diagram showing the relationship between the elongation rate in the tension leveler type scale breaker and the width shrinkage in the scale scraping brush device.
FIG. 2 shows that even if the steel types are different, the elongation rate in the tension leveler type scale breaker 2 and the width shrinkage in the scale scraping brush device 3 are in a proportional relationship.
From this, it is considered that a proportional relationship is established between the width shrinkage in the tension leveler type scale breaker 2 and the width shrinkage in the scale scraping brush device 3.
[0013]
Therefore, the plate width control model in the present invention will be described in detail below.
First, the definitions of symbols are as follows.
Wi: T / L inlet side plate width Wa: T / L outlet side plate width Wb: brush outlet side plate width A: T / L shrinkage allowance B: Brush shrinkage allowance Therefore, the following relational expression holds. .
Wi = Wa + A
Wa = Wb + B
In addition, since a proportional relationship is established between the width shrinkage in the tension leveler type scale breaker 2 and the width shrinkage in the scale scraping brush device 3,
Assuming B = K * A,
The relational expression Wa = (K * Wi + Wb) / (1 + K) can be derived.
[0014]
Here, K is the ratio of the width shrinkage in the tension leveler type scale breaker 2 to the width shrinkage in the scale scraping brush device 3, and can be calculated in advance from the actual data.
In this way, it is possible to determine the target value of the outlet side plate width Wa of the tension leveler type scale breaker 2 in order to keep the plate width Wb on the outlet side of the brush within a certain range.
By measuring the Wa actual value with the plate width meter 5 and controlling the tension of the bridle roll 1 so that this value approaches the target value, the plate width on the brush exit side can be within a specified range, The plate width control error can be improved by 2 mm at maximum compared to the control model that does not take into account the reduction width of the conventional brush.
[0015]
【The invention's effect】
According to the present invention, in a steel strip production line having a tension leveler type scale breaker and a scale scraping brush device, the scale scraping brush device of the scale scraping brush device using a plate width meter installed on the exit side of the tension leveler type scale breaker. It is possible to provide a method for performing highly accurate plate width control that can make the plate width on the exit side within a specified range, and there is an industrially useful and remarkable effect.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a plate width control model in the present invention.
FIG. 2 is a diagram showing a relationship between an elongation rate in a tension leveler type scale breaker and a width shrinkage in a scale scraping brush device.
[Explanation of symbols]
1 ... Bridle roll 2 ... Tension leveler type scale breaker (T / L)
3 ... Scale scraping brush device (brush)
4 ... T / L inlet side plate width meter 5 ... T / L outlet side plate width meter 6 ... main motor 7 ... elongation motor 8 ... process computer 9 ... controller

Claims (1)

Sheet width control in a steel strip production line with a tension leveler scale breaker between a pair of bridle rolls that apply tension to the steel strip, and a scale scraping brush device that scrapes off the scale easily removed by this breaker. a method, to be within a specified range of the plate width on the delivery side of the scale scraping brush device is set in advance, determines a target value of the plate width at the outlet side of the tension leveler type scale breaker, the A sheet width control method in a steel strip production line, characterized in that the sheet width is controlled so that the actual value of the sheet width on the exit side of the tension leveler type scale breaker approaches the target value.

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